Developing materials strategies to control siRNA spatial and temporal delivery to engineer multicomponent tissues

ID：MPS/DMR/BMAT（7623）1206219 PI：Benoit，Danielle ORG：University of Rochester罗彻斯特大学开发材料策略来控制siRNA的空间和时间传递，以工程化多组分组织智力优势：小干扰（siRNA）是一种强大而特异的基因沉默机制，可以启动控制干细胞分化的信号级联。 因此，siRNA可以为再生医学应用提供指导干细胞分化的有力线索。 然而，提供siRNA的模式化、局部化和有效递送的技术的开发对于实现这种潜力至关重要。 这项工作的目的是纳入和控制聚合物纳米颗粒（NP）的图案化，以在水凝胶内递送siRNA，从而影响包封的间充质干细胞（MSC）分化，其中MSC是能够分化为肌肉骨骼谱系细胞的多能前体细胞。 PI的目的是开发水凝胶支架，可以用强大的siRNA分化线索进行图案化，能够指导MSC的成骨和软骨分化，用于骨软骨组织工程应用。 已经建立了四个技术目标来实现这一目标：（1）组装和表征siRNA/聚合物纳米颗粒（NP）以指导MSC成骨和成软骨分化。 (2)利用控制释放化学物质来维持siRNA从水凝胶中或在水凝胶内的释放。 (3)开发用于水凝胶微环境中siRNA/聚合物NP的空间微图案化技术。 (4)利用时空调节的siRNA/聚合物NP的可用性在体外发育成骨、成软骨和骨软骨组织。 这些目标的结果将建立由siRNA在水凝胶微环境内诱导的MSC分化。 此外，它将证明时空控制的分化线索的传递可以用来开发复杂的组织结构。 这些发展将促进和扩大siRNA在再生医学和其他领域的许多治疗应用中的效用，其中需要空间和时间的储库递送。更广泛的影响：超过50%的骨科损伤涉及关节内骨软骨组织的损伤。 由于缺乏再生策略，这些损伤通常进展为不可逆的退行性骨关节炎。 这项工作将开发利用空间和时间控制的siRNA治疗骨软骨组织再生的方法。 然而，该方法可以容易地针对任何多组分组织的工程化进行定制。 除了预期的科学成果，PI还计划了各种活动来教育非工程师，以及招募和留住工程领域的妇女和代表性不足的少数民族。 具体来说，PI将积极主动地与UR计划合作，旨在增加多样性，并使高中生接触到工程领域可能的职业机会。 这些方案包括：每年夏天接待和指导Xerox，Kearns和SURF学生，为UR的夏季学者计划开发和教授动手实验室实验，与UR的Women In Engineering Group合作，在我们的实验室举办活动并与来访的学生团体交谈，接待阴影高中学生，并在许多公共活动中发言，教育公众工程对社会的影响（例如，WXXI健康星期五广播节目，年度伯努瓦实验室亚历克斯的柠檬水立场）。

ID: MPS/DMR/BMAT(7623) 1206219 PI: Benoit, Danielle ORG: University of RochesterTitle: Developing materials strategies to control siRNA spatial and temporal delivery to engineer multicomponent tissuesINTELLECTUAL MERIT: Small interfering (siRNA) is a powerful and specific gene silencing mechanism that can initiate signaling cascades governing stem cell differentiation. Thus, siRNA may provide potent cues to direct stem-cell differentiation for regenerative medicine applications. However, development of technology to provide patterned, localized, and efficacious delivery of siRNA is crucial for realizing this potential. The objective of this work is to incorporate and control the patterning of polymer nanoparticles (NPs) to deliver siRNA within a hydrogel to affect encapsulated mesenchymal stem cell (MSC) differentiation, where MSCs are multipotent precursor cells capable of differentiating into cells of the musculoskeletal lineage. The PI aims to develop hydrogel scaffolds that can be patterned with powerful siRNA differentiation cues capable of directing osteogenic and chondrogenic differentiation of MSCs for osteochondral tissue engineering applications. Four technical objectives have been established to achieve this goal: (1) Assemble and characterize siRNA/polymer nanoparticles (NPs) to direct MSC osteogenic and chondrogenic differentiation. (2) Exploit controlled release chemistries to sustain the release of siRNA from or within hydrogels. (3) Develop spatial photopatterning techniques for siRNA/polymer NP within hydrogel microenvironments. (4) Exploit spatiotemporally regulated siRNA/polymer NP availability to develop osteogenic, chondrogenic, and osteochondral tissue in vitro. The results of these objectives will establish MSC differentiation induced by siRNA within hydrogel microenvironments. Moreover, it will demonstrate that delivery of spatiotemporally controlled differentiation cues can be exploited to develop complex tissue structures. These developments will advance and expand the utility of siRNA for numerous therapeutic applications within regenerative medicine and beyond, where spatial and temporal depot delivery is required.BROADER IMPACTS: Over 50% of orthopaedic injuries involve damage to osteochondral tissues within articular joints. Due to the paucity of regenerative strategies, these injuries commonly progress to irreversible degenerative osteoarthritis. This work will develop the means to exploit spatially and temporally controlled siRNA therapeutics for osteochondral tissue regeneration. However, the approach can readily be tailored for the engineering of any multicomponent tissue. Beyond the anticipated scientific results, the PI has planned a variety of activities to educate non-engineers as well as to recruit and retain women and underrepresented minorities in engineering. Specifically, the PI will be proactive in working with UR programs aimed at increasing diversity and exposing high school students to possible career opportunities in engineering. These programs include: hosting and mentoring Xerox, Kearns, and SURF students each summer, developing and teaching hands-on laboratory experiments for UR's Summer Scholars Program, working with UR's Women In Engineering Group to host events in our laboratory and speak to visiting student groups, hosting shadowing high school students, and speaking at numerous public engagements to educate the general public about engineering's impact in society (e.g., WXXI Healthy Friday radio program, Annual Benoit Laboratory Alex's Lemonade Stand).